Safety device for food waster disposer



March 12, 1963 l. MOSKOVITZ 3,081,042

SAFETY DEVICE FOR FOOD WASTE DISPO SER Filed Sept. 15, 1960 INVENTOR. lievnvc; MOS/(OV/TZ' posal apparatus.

ation, damage to either or both the object and the compassing through the entry port.

' SAFETY DEVICE FOR FOOD WASTE DISPOSER Irving Moskovitz, Monterey Park, Calih, assignor of one-half to Ernest J. White, Los Angeles, Calif. Filed Sept. 15, 1960, Ser. No. 56,278 '7 Claims. (Cl. 241-36) .The. present invention relates to a safety device for food waste disposal apparatus nad more particularly to I such a device which prevents damage to both the comminution elements of the disposal apparatus and to objects such as silverware or the like when such an object falls into the comminuting chamber of the disposal apparatus.

Inmost commercial and domestic kitchens, the food "waste disposer is considered a standard fixture because of convenience, reliability and sanitary reasons. The waste disposal apparatus is mounted beneath a sink and has an 1 entry port for its comminuting chamber in alignment with the drain opening of the sink.

When dishes are being washed in the sink, frequently smaller objects such as silverware, bottle openers or the like inadvertently fall through the drain opening of the sink and into the comminuting chamber of the waste dis- In the event the disposer is in operminution elements of the disposer is imminent. When the waste disposer is not in operation and an object, such as silverware, inadvertently falls into the comminuting chamber, damage to the object. and comminution elements of the disposer will occur as soon as the disposer begins operating. .ln most instances, the person washing dishes or using the food waste disposer is not aware that an object has fallen into the comminuting chamber of the disposer.

Generally, the first indication of the problem is the grinding. and clanging noise of the object within the disposer comminuting chamber, with the damage already having occurred. There is no known device heretofore for solving this problem.

The present invention simply, reliably and completely solves this problem of when an object falls into the comminuting chamber of a waste disposer by automatically stopping the motor, of the disposer when in operation and j by automatically preventing the operation of the disposer I when inoperative. In general, the present invention proyides'a safety device comprising a current-carrying elec- 3,981fi42 Patented Mar. l2, 1963 considered in connection with the appended drawings.

- poser (phantom lines) mounted beneath the sink and an In the drawings: FIG. 1 is a perspective view of a sink, a waste disexemplary sensing means of the present invention surrounding the entry port of the comminuting chamber of the disposer;

FIG. 2 is a top plan view of the exemplary currentcarrying electrical sensing means of the device shown in motor to open and therefore prevent the motor from being operated. Therefore, even if a conductive object inadvertently falls int-0 the disposer comminuting chamber, the safety device automatically operates to prevent damage. In order to again operate the waste disposer, a

l I reset switch is required to be actuated.

Accordingly, it is a general object of the present invention to provide a safety device for food waste disposers that solves and avoids problems and disadvantages of similar type waste disposers used heretofore.

An object of the present invention is to provide an automatically operated safety device for food waste disposal apparatus to prevent damage when an object falls into the comminuting chamber of the disposal apparatus.-

Another object is to provide a safety device for food waste disposal apparatus which is automatically operated FIG. 1; 1

FIG. 3 is a block diagram of a typical circuit that may be used with the device of the present invention;

FIG. 4 is an exemplary schematic wiring diagram that may be used with the device of the present invention;

FIG. 5 is a fragmentary, exploded perspective view of an exemplary electrically actuated brake that may be connected with the disposer motor of the present invention.

It should be understood that the safety device of the present invention may be used on food waste disposal apparatus for commercial or domestic kitchens. In its broadest aspect, the present invention includes an electrical sensing means'positioned around the entry port of a disposer comminuting chamber and an electrical circuit connecting the sensing means to the motor of the waste disposer. The sensing means is responsive to and actuated by a conductive object passing into the disposer comminuting chamber for stopping the motor or preventing the motor from being operated until a reset switch is manually actuated to reset the circuit. The device opcrates automatically even if the object inadvertently passes into the disposer comminuting chamber.

An exemplary device of the present invention is shown in the drawings and includes a waste disposal apparatus 10 mounted beneath a sink 11. It is understood that the disposer 10 may be of well known design and includes a comminuting chamber, an entry-port for the chamber, comminution elements within the chamber and an electrical motor for driving the comminution elements; The entry port for the disposer comminuting chamber is in vertical alignment with the drain opening 12 of the sink 11. in the exemplary device 10 shown in FIGS. 1 and 2, splash guards'13 may be provided within the drain opening 12 and may be utilized as support means for an exemplary embodiment of the present invention as described in greater detail hereinafter.

Current-carrying electrical sensing means 15 is positioned around the entry port to the comminuting chamber and is responsive to the presence of a conductive object which passes through the entry port and into the comminuting chamber. One exemplary embodiment of the sensing means 15 is shown in PEG. 2 as elongated strips A and B of conductive material secured around the edges of the splash guards 13. The sensing strip A is provided on alternate splash guards 13a and as best seen in FIG. 2, is continuous and extends beneath the base of splash guards 13b carrying the sensing strips B and is electrically connected to the motor of the disposer as seen in the exemplary circuit diagram of FIG. 4. The electrical sensing strips B are provided on splash guards 13b and are grounded to the frame of the disposer casing. The sensing elements A and B are of opposite polarity and therefore provide alternate probes or sensing elementswhich protrude radially into the drain opening and across the entry port to the disposer comminuting chamber. When a conductive object falls through the drain opening and into the entry port of the disposer comminuting chamber, the electrical sensing elements A and B will be short-circuited and as explained in detail hereinafter, will cause the safety device of the present invention to be actuated.

The metallic sensing strips A and B may be laced wire or may be made of other conductive flexible material to allow these sensing elements to be secured to the splash guards 13. It is understood that the number of sensing elements shown are only illustrative and the invention is not limited to any specific number of sensing elements. Moreover, in accordance with the basic teachings of the present invention, the sensing elements should be positioned around the entry port and should be responsive to the presence of a conductive object which passes through the entry port.

FIG. 3 discloses a schematic block diagram of a basic circuit which may be utilized with the present invention. The circuit should include sensor elements 15 connected to a relay system 17 which is adapted to open and close in accordance with the presence of a conductive object passing through the sensors. The relay 17 controls the supply of electrical energy to a motor 16 and brake 27. An exemplary schematic diagram is shown in FIG. 4 and it is understood that other circuits may be utilized than that shown in FIG. 4. It should be noted that an amplifier 20 may be provided in the block diagram of FIG. 3 as it is contemplated that the signal received from the sensing elements 15 may be required to be amplified in order for the electrical circuit to be actuated. However, the amplifier 20 is not required to be provided in a basic schematic diagram as shown in FIG. 4.

The motor 16 of a Waste disposal apparatus may be supplied electrical energy by means of an AC. source through line contacts L and L Line contact L is connected to one side of the motor and line contact L is connected to the other side of the motor through a sensitive relay 17 and a power or on-oii switch 18. Currentcarrying electrical sensing means 15, such as the sensing strips A and B, may be energized by means of the line voltage through a step-down transformer 19 wherein the primary side of the transformer 19 is connected to the line contacts L and L One side of the secondary winding of the transformer 19 is connected directly to the sensor element B and the other side is connected through a resistor 21 and germanium, silicone or similar diode 22 to one side of the coil of the relay 17. The other side of the coil of the relay 17 is connected directly to the sensor element A. A smoothing capacitor 23 may be connected between the secondary winding of the transformer 19 and the coil of the relay 17 and grounded.

In addition, a pilot light 24 and current-limiting resistor 25 may be connected across the coil of the relay 17, in accordance with standard circuit practice.

The relay 17 may have upper and lower arms and in its normal position, the upper arm is in electrical communication with contact 17a so that a complete circuit is provided for operating the motor 16 of the waste disposer. The upper arm of the relay is adapted to be moved downwardly and is adapted to electrically communicate with contact 17b for purposes described hereinafter. The lower arm of the relay 17 is adapted to engage contact 176 or the relay coil when the relay coil is energized, but in its normal position is not in contact with 170.

It has been found that braking means may be provided to the shaft of the motor 16 for immediately stopping the motor when the sensor elements A and B are shortcircuited. Therefore a brake 27 may be mechanically connected to the shaft of the motor 16 and is electrically connected to contact 17b of the relay 17 and to the other side of the line voltage at L A reset switch or push button 28 may be provided for the relay 17 for manually moving the relay into its normal position or resetting the circuit after the sensor elements A and B have been short-circuited. This reset switch 28 may be connected to the lower arm of the relay 17 and to the other sensor element B.

It is understood that dependent upon the sensitivity of the system, the various components of this exemplary circuit may have different and varying values. However, the exemplary circuit as described and shown in FIG. 4 may have the following values: 117 v. for the line voltage at L and L 1.5 v. to 20 v. for the sensitive relay 17; 1.5 v. to 20 v. for the pilot light which serves as an indicator and transient suppressor; a 5 ohm resistor 21; 5 to 0 mfd. capacitor 23; and a 1.5 to 20 v. stcptlown transformer 19 from 117 v.

In operation, there are two possible situations in which the safety device of the present invention will be actuated. The first is when the on-off switch 18 is closed and the motor 16 is in operation, and the second is when the switch 18 is opened and the disposer motor 16 is inoperative.

Operation When Disposer Is Running In this situation, theupper arm of the relay 17 is in cont-act wit-h 17a and electrical energy is supplied to the motor 16'. When a conductive object, such as silverware, falls through the entry port of the comminuting chamber and short-circuits the sensor elements A and B, a complete circuit is provided for the coil of the relay 17. The relay coil is thus energized and the upper and lower arms of the relay 17 are attracted by and move downwardly towards the contacts 17b and 170, respectively, of the relay 17. This breaks the circuit to the motor 16 as the upper arm is now out of contact with 17a. The lower arm of the relay 17 engages contact of the relay coil and the upper arm of the relay 17 engages contact 17b which completes the circuit to the brake 27. This immediately causes the brake 27, which is electrically actuated, to stop the motor 16 and comminution elements within the waste disposer.

This prevents damage to both the conductive object which fell into the comminuting chamber of the disposer and to the comminution elements within the chamber. The waste disposal apparatus 10, at this stage, cannot be actuated even if the conductive object is removed from or falls through the sensing elements 15 and into the comminuting chamber of the disposer without manually actuating the reset switch 28. This provides a positive means for preventing further damage until the conductive object is removed and the circuit is reset. To reset the circuit, the switch 28 is manually actuated to again move the relay arms upwardly and away from contacts 17!; and 170 and into contact with 17a. This breaks the circuit to the brake 27 and again completes the circuit to the motor 16 of the disposer. When the on-oi'f switch 18 is again operated, the disposer will actuate.

Operation When Disposer Is Inoperative In this condition, power switch 18 is in the off position and the motor 16 is inoperative. When a conductive object actuates the sensing means 15, the coil of the relay 17 will again be energized and the relay arms will again be moved downwardly and into contact with 1717 and 17:: to break the circuit to the motor 16 and actuate the brake 27. When it is desired to again use the waste disposal apparatus, power switch 18 is turned to the on position but the motor 16 will not operate as the circuit to the motor is open. This is an indication to the user that a conductive object has passed into the comminuting chamber and has actuated the safety device. After removing the conductive object from the chamber, the reset switch 28 should be manually actuated to reset the circuit.

It can therefore be seen that a relatively simple circuit may be utilized to connect the current-carrying electrical sensing means 15 with the motor 16 so that the supply of electrical energy to the motor 16 will be discontinued when a conductive element passes through the sensing means and entry port of the disposer comminuting chamber. It should be understood that other circuits could be utilized and that either AC. or DC power could be provided to the sensing means 15. However, a relatively low voltage should be supplied to the sensing means 15 at all times as it may be required to manually remove the conductive object from within the sensing means. Probably ID V. would be sufficient to cause the sensing means to be actuated and to provide a relatively low voltage for safety reasons.

Various types of electrically actuated brakes may be used in the present device. An exemplary brake 27 is disclosed in FIG. 5 and may include a stationary disc 31 secured to the casing of the motor 16, a spline shaft 32 directly coupled to the shaft of the motor 16, and a circular brake disc 33 secured to the other end of the spline shaft 32 and including a suitable and well known type of brake material on the inside surface thereof. A compression or coil spring 34 is provided between the motor casing and the brake disc 33 to return the brake disc to a non-stopping position. An actuating solenoid 35 may be provided and is electrically connected to contact 17b of the relay 17 and to the other side of the line voltage at L The actuating solenoid 35 is provided with a movable armature 36 and a pusher bearing 37 is connected to the outer end of the armature 36. When the solenoid 35 is energized, the armature 36 and pusher bearing 37 are moved upwardly and forces the brake disc 33 into frictional contact with the stationary disc 31. The solenoid 35 is energized when the relay 17 is moved downwardly in response to a short-circuiting of the sensor elements A and B. When the sensor elements A and B are not short-circuited and after the relay 17 has been reset, the solenoid is not energized and the brake disc 33 is forced downwardly by spring 34 and away from the stationary disc 31 into a non-braking position.

It can therefore be seen that the safety device of the present invention will be automatically actuated when the waste disposer is in operation or is inoperative. When operating, the disposer motor 16 will be immediately stopped when a conductive object passes into the comrninuting chamber of the disposer. When the disposer is not operating, the circuit to the motor of the disposer will be opened when a conductive element actuates the sensing means located at the entry port of the comminuting chamher. In either condition, the reset switch 28 is required to be actuated to reset the circuit.

The present invention therefore completely eliminates the problems of other waste disposal apparatus used heretofore. The present device is reliable, extremely economical to install and is automatically operated. It can be easily understood by those skilled in the art that the present invention may be assembled on existing Waste disposal apparatus economically and with a minimum of time.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. For example, it is contemplated that other current-carrying electrical sensing means may be utilized than the specific sensing elements A and B shown and described herein. However, in accordance with the present invention, the sensing means should be responsive to the presence of a conductive object so as to discontinue the supply of electrical energy to the motor of the waste disposer. -It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

I claim:

1. In combination with a waste disposal apparatus including a comminuting chamber, entry port for said chamber, comminution elements within said chamber, and electrical motor for driving said comminution elements, an automatically operated safety device comprising: current-carrying electrical sensing means positioned around said entry port and responsive to the presence of a conductive object passing through said entry port, and circuit means connecting said current-carrying electrical means with said motor for discontinuing the supply of electrical energy to said motor when a conductive object passes through said entry port.

2. In combination with a waste disposal apparatus as stated in claim 1, including an electrical actuated brake connected to said motor, and wherein said circuit means is connected to said brake and includes means for actuating said brake and stopping said motor when a conductive object passes through said entry port.

3. In combination which a waste disposal apparatus as stated in claim 1, wherein said circuit means includes a relay for maintaining the circuit in an open condition so that the supply of electrical energy to the motor is discontinued when a conductive object has passed through said entry port, and a reset switch for resetting said c1rcu1t.

4. In combination with a waste disposal apparatus including a comminuting chamber, entry port for said chamber, splash guard elements secured to and around the walls of said entry port and extending radially into said entry port, comminution elements within said chamber, and electrical motor for driving said comminution elements, an automatically operated safety device comprising: current-carrying electrical sensing means carried by said splash guard elements around said entry ports and responsive to the presence of a conductive object passing through said entry port, and circuit means connecting said current-carrying electrical means with said motor for discontinuing the supply of electrical energy to said motor when a conductive object passes through said entry port.

5. In combination with a waste disposal apparatus as stated in claim 4, including an electrical actuated brake connected to said motor, and wherein said circuit means is connected to said brake and includes means for actuating said brake and stopping said motor when a conductive object passes through said entry port.

6. In combination with a waste disposal apparatus as stated in claim 4, wherein said circuit means includes a relay for maintaining the circuit in an open condition so that the supply of electrical energy to the motor is discontinued when a conductive object has passed through said entry port, and a reset switch for resetting said circuit.

7. In combination with a waste disposal apparatus as stated in claim 4, wherein said current-carrying electrical sensing means comprises elongated strips of conductive material secured around the edges of said splash guards.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN COMBINATION WITH A WASTE DISPOSAL APPARATUS INCLUDING A COMMINUTING CHAMBER, ENTRY PORT FOR SAID CHAMBER, COMMINUTION ELEMENTS WITHIN SAID CHAMBER, AND ELECTRICAL MOTOR FOR DRIVING SAID COMMINUTION ELEMENTS, AN AUTOMATICALLY OPERATED SAFETY DEVICE COMPRISING: CURRENT-CARRYING ELECTRICAL SENSING MEANS POSITIONED AROUND SAID ENTRY PORT AND RESPONSIVE TO THE PRESENCE OF A CON- 